EE WAS PRE SHIFTING THE WORKING FACES. HE STOPPED IN THE L.O.B. BETWEEN #6 & #7 FACES TO TALK TO THE ROOF BOLTING CREW. HE KNELT DOWN ON HIS KNEES. A PIECE OF ROCK MEASURING 30""X 16""X 3"" FELL OUT HITTING HIS BACK. HE WAS ADVISED TO REMAIN OFF WORK 1 WEEK.